Measurement of thermal diffusivity of nonlinear optical polymer thin filmsusing photoacoustic method

We developed an apparatus to measure the thermal diffusivity of a nonlinear optical (NLO) polymer thin film where the measurement was based on the pho toacoustic method. The validity of the measured data was verified by compar ison with published ones for Ti and Pt metallic foils. The thermal diffusiv ity of a polymer thin film, polymethyl methacrylate (PMMA) with Disperse Re d 1 (DR1) chromophore side group, is independent of the thickness and the p ercentage of the chromophore, and is almost constant at 6 x 10(-8) m(2)/s. The thermal diffusivity of the electrically poled NLO polymer thin film is independent of the intensity of the applied electric field.